(A) GFAP levels are elevated during oxidative stress as determined by immunoblot assay (B) During oxidative stress GFAP levels are significantly upregulated versus mock (**, p=0.0020). 25 μM estrogen pretreatment for 18 h (**, p=0.0022) or 2 h (**, p= 0.0074) significantly reduced GFAP levels compared to tBHP treated ONHAs. When compared to mock treated ONHAs both 2 h (ns, p=0.3054) and 18 h (ns, p=0.0954) estrogen pretreatment had no significant changes to the levels of GFAP. GFAP levels showed no significant difference when comparing estrogen pretreatment for 2 h or 18 h (ns, p=0.4926). Experiments were done in triplicate (n=3) and values were depicted as mean +/− SEM and analyzed using ANOVA (p=0.0002). For statistical comparison, the Bonferroni post-hoc test and Student t-test were used. Statistical significance was set at p ≤ 0.05.